1. Field
The present invention relates to network interface units, and more particularly, to network interface units that employ flow control.
2. Background Information
As is well known, when a port of a network interface unit (NIU) is configured to operate in full-duplex mode, congestion may result due to a shortage of internal resources, such as, for example, due to the filling of buffers that receive packets of information signals. Because, typically, limited memory is available for buffering these data signals, and limited memory is available for forwarding these signals as well, flow control signaling may be employed. See, for example, the CSMA/CD Access Method Standards Package, available from the Institute of Electrical and Electronics Engineers, Inc. (IEEE), New York, N.Y., which includes the IEEE standard 802.3u-1995. Typically, the congestion problem is alleviated by sending flow control frames in a full-duplex network configuration, or alternatively, by applying back pressure in a half-duplex network configuration. This flow control frame is employed to reduce the risk that the other side of the network does not transmit a frame to an already congested switch or other device. However, because this flow control frame is sent across the sent across the network, it may result in additional traffic and even collision. Therefore, employing flow control may decrease congestion, but it may also degrade performance. A need, therefore, exists for a method or technique for addressing the congestion of a network interface unit (NIU), while reducing the degradation in performance of the network.
Briefly, in accordance with one embodiment of the invention, a system includes: a network interface unit (NIU). The network interface unit (NIU) is adapted to monitor bandwidth utilization of the network interface unit and adjust the minimum interval for the transmission of a flow control packet, based, at least in part, on the bandwidth utilization determination.
Briefly, in accordance with another embodiment of the invention, an apparatus includes at least one integrated circuit. The integrated circuit includes the capability, either alone or in combination with other integrated circuits, to monitor the receive rate utilization of a network interface unit and adjust the minimum interval for the transmission of a flow control frame, based, at least in part, on the receive rate utilization determined.